Definition - What does Filament Winding mean?
This is a manufacturing technique used in the making of structures and parts through continuous winding of fibers onto a rotating mandrel by maintaining a placement pattern that controls the uniformity of the structure.
It is used in the making of hollow composite parts like tanks, cylinders, tube and pipes; it is also considered as the casing of oval or circular cores to reduce the cost of manufacturing through other methods. These parts are used in the aerospace industry, energy production industries (wind, oil and gas) and CNG Transportation.
Corrosionpedia explains Filament Winding
Filament winding consists of two methods used in the manufacturing of components; these include:
- Wet winding
- Dry winding
In wet winding, the fibers are unwound from roving and passed through a bath of resin mixture—impregnation process—before it is wound on a mandrel of defined orientation. The pattern of placement is controlled by the rate of rotation of the mandrel and the feeding or metering mechanism. Whereas the dry method uses fibers in their pre-impregnated form (towpreg composite fabrics).
When the right layer thickness is achieved, the assembly is cured in an oven. After curing, the core can be removed or used as part of the finished part. During curing, crosslinking occurs and thus forms 3D network fibers. The winding angle will determine the properties like strength (tensile and circumferential) and the strength to weight ratios. The compactness comes from the tension of the fiber during winding.
The CNC machines used in filament winding control all the processes that produce tension, speed and temperature. The composite parts made through these methods are generally lightweight in nature. The profile of the mandrel of core resembles that of the finished product.